This invention relates to a train control system for controlling the operation of trains that run based on a planned schedule.
Conventionally, trains have been run by being dependent on the experience of train drivers. At the departure of one station, the driver is given only information on the scheduled arrival time and departure time of the next station. The driver runs the train by experience in consideration of the load factor, the slope in each railroad section, the speed limit imposed by signals and curves of railroad, the energy conservation, the ride comfort, etc., and uses a marginal time arbitrarily during a run and a stop at the next station until the departure time. If the train operation schedule is disrupted by bad weather or accident, the operation control equipment in the central control office determines a modified schedule and issues an inter-station run time that is based on the modified schedule to the train driver, and the driver runs the train within the modified inter-station run time.
For the security of the train operation, there is used the automatic train control (ATC) system. The ATC system is designed to divide the railroad between stations into multiple sections and impose a speed limit on the rear-running (latter) train depending on the number of free sections left behind the front-running (former) train, i.e., the fewer the number of free sections ahead of a train, the more severe speed limitation is imposed on the train, as described in Japanese patent publication JP-A-48-64604.
Conventionally, the train driver uses a marginal time arbitrarily during the period between stations and does not know the immediate position and speed of the former train. Consequently, the train runs as usual even if the former train reduces the speed due to bad weather or accident, resulting in the application of the ATC-based speed limitation and the incompliance of the specified inter-station run time. Moreover, the speed limitation imposed on one train causes another speed limitation on the latter train, and this adverse effect propagates one after another to exhibit the "accordion phenomenon", resulting in an aggravated disruption of the operation schedule.
During the recovery period of the disrupted schedule through the application of a modified schedule, the train driver who is allowed to use arbitrarily a marginal time included in the modified schedule tends to run the train at the highest-possible speed within the limit with the intention of restoring the train schedule. As a result, the train comes too close to the former train, which often incurs the accordion phenomenon and the retardation of schedule recovery.
The conventional train control scheme is vulnerable in that once the operation of a train is disrupted, it is liable to propagate to the following trains and the operation plan needs to be altered ultimately in many cases. Another problem is a slow recovery to the original schedule during the application of an altered schedule.